I have zero idea why they won't offer a 55g version because the domes exist for that model. I have a Abko Hacker 55G and it works great. The 55G domes feels so much nicer than the 35 or 45 and come quite close to legitimate Topre.

I received my 45g model yesterday (from Aliexpress). It is quite nice. It feels a lot like a 45g Topre with Hypersphere silencing rings, which is to say the tactility is softer than normal, but I'm okay with that.